Vibratory bulldozer

ABSTRACT

There is disclosed a bulldozer with vibratory means operatively connected to the blade and operative to increase the amount of work that can be done by a given sized tractor at a given time.

United States Patent Allen et al. 1 Oct. 2 1973 1 1 VIBRATORY BULLDOZER 3.238.646 3/1966 Oldenburg 172 40 x 3,473,242 10/1969 Martin 172/40 X [75] Inventors. J8: K. Allen, Chilllcothe, Logan J. 2.986194 5H9 Gramyd I l72/40 X East Pe0m1- both of 2,499,620 3 1950 Alderman 172 40 [73] Assignee: Caterpillar Tractor Co., Peoria, 111.

- Primary ExaminerRobert E. Pulfrey [22] Flled' 1971 Assistant Examiner stephen C. Pellegrino 1211 Appl. No.: 207,074 Att0rneyFreling E. Baker et al.

[52] US. Cl. 172/40, 172/801 57 ABSTRACT [51] Int. Cl A01b 35/00 [58] Field of Search 172/40 37/141 There IS disclosed a bulldozer with vibratory means operatively connected to the blade and operative to in- [56] References Cited crease the amount of work that can be done by a given UNITED STATES PATENTS sized tractor at a given time. 3,443,327 5/1969 Martin 172/40 X 9 Claims, 6 Drawing Figures PATENIED 0m 2 3 SHEET 10F 5 INVENTORS JAN K. ALLEN LOGAN 3. JOHNEON K7 r La -,4,

ATTORNEYS PATENTEDUCI '21915 SHEET 2 BF 5 BY W PATENTEDUCT- 2m sum 3 [1F s INVENTORS 7 JAN K. ALLEN LOGAN .mor-msou BY 6, a W W 4%, 4 #47 ATTORNEYS PATENTEUUBT "2 3.762.481

SHEET 5 BF 5 INVENTORS N K N EN ATTORNEYS TOTAL DVBPLACLMLNT APPROX \O' B BY LOGAN JJOHNSON 1 VIBRATORY BULLDOZER BACKGROUND OF THE INVENTION The present invention relates to a bulldozer blade and pertains more particularly to a bulldozer blade provided with an exciter mechanism operatively connected to transmit vibratory energy to the blade.

One of the majon limitations of an earthmoving vehicle is the traction that the vehicle is able to develop to impose a force against an earth formation. In other words, more often than not the force that a vehicle such as a bulldozer or the like is able to develop is dependent more on the reaction forces the vehicle is able to develop between the driving wheels and the supporting earth than on the horsepower ratings of the engine or prime mover of the vehicle.

One way of improving the traction of a vehicle is to increase the weight of the vehicle by attaching weights thereto. This, however, is a disadvantage in that it often times defeats the very purpose for which the weight is added because it then takes more engine horsepower to move and maneuver the vehicle. This added weight also increases the burden and expense of transporting the vehicle. In summary, the productivity of a conventional bulldozer or earthworking vehicle is almost directly related to the size and weight of the vehicle.

High productivity of earthmoving vehicles is often required in remote areas such as flood-damaged areas, earthquake-damaged areas and in military operations where transportation facilities and roads are often not available to move large vehicles into the area. It is, therefore, desirable to have small, high-productive vehicles for use in such remote areas. Numerous attempts to improve the productivity of earthmovingvehicles have proven unsuccessful.

Considerable effort has been put into attempts to develop and improve the productivity of a vehicle by applying vibration to the earthworking implement or blade. Examples of such prior art attempts are disclosed in the following U.S. Pat. Nos.: 3,437,381 issued Apr. 8, 1969 to A.G. Bodine; 3,443,327 issued May 13, 1969 to W.E. Martin; and, 2,499,620 issued Mar. 7, 1950 to B. T. Alderman.

SUMMARY OF THE INVENTION It is, therefore, a primary object of the invention to provide means for considerably increasing the productivity of a given size earthmoving vehicle.

A further object of the present invention is to provide means for increasing the productivity of an earthmoving vehicle for a given tractive effort.

A further object of the present invention is to provide means for applying vibratory energy to the earthworking blade of an earthmoving vehicle in such a manner as to considerably improve the productivity of said vehicle.

A still further object of the present invention is to provide improved means for applying vibratory energy to the blade of an earthworking vehicle.

In accordance with the present invention, means are provided for applying vibratory energy to the blade of an earthworking implement. The vibratory means is operative to apply considerable vibratory energy to the blade in a direction and at a rate that will reduce the force necessary to move a given amount of material.

BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned and other objects and advantages of the present invention will become apparent from the following specification when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a bulldozer incorporating a preferred embodiment of the present invention;

FIG. 2 is a detailed elevational view, partially in section, of a preferred embodiment of the present invention;

FIG. 3 is a plan view, partially in section, of the embodiment of FIG. 2;

FIG. 4 is a sectional view taken generally along lines IV IV of FIG. 3;

FIG. 5 is a diagrammatic illustration of the motion of the present invention; and,

FIG. 6 is a schematic of an exciter drive circuit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1 of the drawings, there is illustrated a vibrating bulldozer arrangement, generally indicated at 10, which is pivotally supported at 12 to a pair of push arms 14, which are in turn pivotally supported at 16 to the track roller frame 18 of a track-type tractor 20. The bulldozer arrangement comprises an intermediate support frame 22 to which is pivotally connected at 24, a pair of lift motors or jacks, one of which is shown at 26. The lift jacks 26 raise and lower the bulldozer blade arrangement with respect to the tractor and ground surface in a conventional manner. The bulldozer blade arrangement can also be tilted or pitched forwardly or rearwardly with respect to the ground, or tilted laterally by means of a pair of pitch and tilt jacks, one of which is shown at 28, all in a well known manner.

The intermediate frame assembly 22 supports the vibrat'or exciter mechanism and through linkage means supports the bulldozer blade 29 per se. The exciter mechanism and support linkage for the blade is comprised of left and right hand portions with the arrangement being identical to one another.

The right hand exciter arrangement is best shown in FIG. 3. A hydraulic motor 30 is drivingly connected to a crankshaft 36 such as by gear 32 on the motor drive shaft and gear 34 on the end of a crankshaft 36. The crankshaft 36 is journaled to the intermediate frame 22 at 38 and 40 by suitable bearings. The crankshaft 36 has two eccentric throws 42 and 44, which are preferably about out of phase with one another. A connecting rod or pushrod 46 is journaled on throw 42 with its upper end pivotally connected at 48 to a bellcrank 50, as best seen in FIG. 4. The bellcrank 50 is pivotally supported at 52 to the intermediate frame 22. The forward end of bellcrank 50 is operatively connected such as by a pivotal connection at 54 to the upper rear surface of the bulldozer blade.

A pushrod 56 is journaled on eccentric throw 44 with the forward end of the pushrod operatively connected as by pivotal connection directly to the rear surface of the bulldozer blade at 58, as best seen in FIG. 2. With the subject support arrangement, the bulldozer blade is maintained in the substantially vertical position and adapted for substantially straight line vibratory movement at the cutting edge.

3 4 A quill shaft 60 connects the left and right hand ally accelerated during the period that the blade is not crankshafts 36 together to index the rotation of the two in contact with the soil. When the blade hits the soil, hydraulic drive motors. the blade and flywheel decelerate, giving up kinetic en- The push rod 46 during rotation of crankshaft 36 ergy which is transferred into work output at the blade. rocks the bellcrank 50 about pivots 52 On he in rme- 5 The total work input by the two motors during the total diate frame assembly 22. With the forward end of the cl ust ual the work output during the period bellcra k 5 p o dir ly to the baek 0f the blade, when the blade is in contact with the soil for the system the pivot 54 in effect has velocity vector substantially to i i it ain rankshaft R.P M.

perpendicular to a line connecting the pivot 52 on frame 22 and the blade. The push rod 56, which is connected directly to the back of the blade at 58, gives the blade a velocity vector that is dependent on the crankshaft position and the position of the bellcrank 50. The blade should be positioned so as to obtain a medium blade tip velocity vector of between 5 and l0 l5 downward with respect to the ground line and a peakto-peak amplitude or displacement of approximately 1.54 inches. A downward component is generally necessary in order to penetrate downward from ground surface. The top of the blade of a test model that has been constructed has a peak-to-peak amplitude of ap- As illustrated in FIG. 5, the instantaneous center of rotation of the blade 29 is spaced a substantial distance above and in front of the blade, and represented by the point 0. As will be apparent from this diagram, the entire blade undergoes movement. The radius from the instantaneous center 0 to the pivot points 54 and 58 is represented by broken lines R and R. The point and vibratory movement of the blade is such that the radius R and R is very large and the movement of cutting edge 29a is substantially linear, with a vector angle of between 5 and l5. This angle has been found to be about optimum as pointed out above.

proximately 0.75 inches. A 10 medium blade tip veloc- The centers of Pivotal Support drive f ity vector was selected as a result of tests indicating the Hons are h at the center and maxlhmm dfsplace' productivity of the bulldozer blade increased as the vimeht posmohs- These cehters of the Ph Pomts are bration angle (angle between the blade tip velocity vecld'ahufied by the P humbel" The Pivot Points are tor and the ground) decreased for the entire blade viconnected by the center lines 0f the [mks and are so brating arrangement. Tests which have been conducted humberedindicated a productivity to blade angle as follows: 24 The hydraulic mOtOI'S 0 a pr e ably power d by percent increase at 54 percent at 20, 57 percent fluid o a pump d en by the ehicle engine. This at 10, and 64 per ent at 0 a om ared to a m 30 hydraulic drive system is preferably of the type so that vibrating blade and based on a velocity ratio of 5:1. The the hydraulic motors may be driven at variable speed velocity ratio is the ratio of the peak vibratory velocity in order that a suitable velocity ratio may be obtained (a function of the blade frequency and amplitude) of for any working speed of the vehicle. This may be acthe blade tip divided by the tractor velocity. complished by providing either a variable displacement Peak blade tip velocity Amplitude (in.) Exciter rev. 2 1r radius 60 min. 1 mile 2 Minute Revolutions hr. 5280 (12) in. (mile) Mean tractor velocity (1m) A pair of flywheels 62 are keyed to each of the crankpump or a variable displacement motor. Other known shafts 36 and provides stored kinetic energy during one systems may be used. Alternately, the vibratory speed portion of the Cycle and dissipates it in a I th Th may be constant and the vehicle or tractor speed variflywheels 62 also serve to transfer the kinetic energy bl given by the blade as it moves with a sinusoidal motion and its velocity varies from maximum to zero two times each cycle. This transfer is explained as follows:

The dynamics of this system can be best understood from the graphic diagram of FIG. 5. Assume that tip 29a of blade 29 is at mid-stroke (maximum velocity), the blade and the flywheel both have kinetic energy and the velocity is directly dependent. As the blade approaches the end of its stroke, it accelerates the flywheels to a higher velocity so that at the end of the stroke, when the blade velocity is zero (i.e., zero kinetic energy in the blade), the kinetic energy of the A schematic of a hydraulic drive circuit for the exciter circuit is illustrated in FIG. 6 wherein a variable displacement pump 66 supplies fluid by way of conduit 68 to motors 30. A suitable control valve 70 directs fluid for controlling the motors.

In any case, the system should be able to provide a velocity ratio of from 3:1 to perhaps as high as l():l depending on soil conditions. For example, tests indicated that a 3.5:l velocity ratio gave a 30 percent production advantage in medium strength soils such as clay and some wet soils.

flywheels equals the amount initially stored in both the on the th r ha on y a 10 percent advantage was blade and the flywheel and the midstroke position. As obtained in weak soils such as sand.

the drive motors 30 apply a constant torque throughout This construction, in accordance with the present inthe cycle, the mean crankshaft speed is increased. The vention, is capable of increasing the productive capacmotor input is stored in the flywheel as they are graduity of a given size bulldozer. This means that a given size bulldozer can move more material with the vibrating blade of the present invention than with a nonvibrating blade. However, this increased productivity normally does result in an increase in horsepower used or required. This additional horsepower is needed to drive the exciter mechanism, and can ordinarily be supplied by increasing the horsepower of the vehicle engine without otherwise increasing the size of the vehicle.

While this invention has been illustrated with respect to a single embodiment, it is to be understood that numerous changes and modifications may be made in the illustrated embodiment without departing from the spirit and scope of the present invention as defined in the appended claims.

We claim:

1. An earth working apparatus, said apparatus comprising:

a blade for engaging and working an earth formation;

means for adjustably supporting said blade from a mobile vehicle;

eccentric means carried by a rotatable shaft mounted on said supporting means;

a pair of bellcranks pivotally supported by said support means and operatively connected to said eccentric means and to said blade near the top for oscillatory support thereof; and,

a pair of links operatively connected to said eccentric means and to said blade near the bottom thereof for delivering of oscillatory motion thereto at a downward angle with respect to a surface defined by movement of said blade through said formation.

2. The invention of claim 1 wherein said blade pivots about a point spaced above and forward of said blade.

3. The invention of claim 1 comprising variable speed hydraulic means for driving said rotatable shaft.

4. The invention of claim 2 wherein said means for applying vibratory motion to said blade is operative to establish a velocity ratio of said blade of at least 3:1; and,

said vibration is applied at an angle downward from the horizontal.

5. The invention of claim 4 wherein said angle is between 5 and 15 degrees.

6. The invention of claim 4 wherein said means for applying vibratory motion is variable in speed.

7. A vibratory dozer blade means comprising:

a blade, 21 frame for pivotally connecting said blade to a vehicle;

hydraulic means connected between said frame and said vehicle and between said frame and said blade for adjusting said frame relative to said vehicle and said blade relative to said frame;

a rotatable shaft carried by said frame;

power means on said frame operatively connected to rotate said shaft;

an eccentric carried by said shaft; and,

link means operatively connecting said eccentric to said blade to vibrate said blade, said link means including bellcrank means operatively connected to said eccentric and to said blade to support said blade to said frame so that said blade pivots about an imaginary instantaneous center of rotation located above and forward of said blade.

8. The invention of claim 7 wherein the pivotal support of said blade is such that the vibratory motion of said blade has a downward component.

9. The invention of claim 7 wherein said power means is variable, and operative to vibrate said blade at a velocity ratio of at least 3:1. 

1. An earth working apparatus, said apparatus comprising: a blade for engaging and working an earth formation; means for adjustably supporting said blade from a mobile vehicle; eccentric means carried by a rotatable shaft mounted on said supporting means; a pair of bellcranks pivotally supported by said support means and operatively connected to said eccentric means and to said blade near the top for oscillatory support thereof; and, a pair of links operatively connected to said eccentric means and to said blade near the bottom thereof for delivering of oscillatory motion thereto at a downward angle with respect to a surface defined by movement of said blade through said formation.
 2. The invention of claim 1 wherein said blade pivots about a point spaced above and forward of said blade.
 3. The invention of claim 1 comprising variable speed hydraulic means for driving said rotatable shaft.
 4. The invention of claim 2 wherein said means for applying vibratory motion to said blade is operative to establish a velocity ratio of said blade of at least 3:1; and, said vibration is applied at an angle downward from the horizontal.
 5. The invention of claim 4 wherein said angle is between 5 and 15 degrees.
 6. The invention of claim 4 wherein said means for applying vibratory motion is variable in speed.
 7. A vibratory dozer blade means comprising: a blade, a frame for pivotally connecting said blade to a vehicle; hydraulic means connected between said frame and said vehicle and between said frame and said blade for adjusting said frame relative to said vehicle and said blade relative to said frame; a rotatable shaft carried by said frame; power means on said frame operatively connected to rotate said shaft; an eccentric carried by said shaft; and, link means operatively connecting said eccentric to said blade to vibrate said blade, said link means including bellcrank means operatively connected to said eccentric and to said blade to support said blade to said frame so that said blade pivots about an imaginary instantaneous center of rotation located above and forward of said blade.
 8. The invention of claim 7 wherein the pivotal support of said blade is such that the vibratory motion of said blade has a downward component.
 9. The invention of claim 7 wherein said power means is variable, and operative to vibrate said blade at a velocity ratio of at least 3:1. 